1. Field of the Invention
The present invention relates generally to microelectronic structures within microelectronic fabrications. More particularly, the present invention relates to microelectronic structures fabricated with enhanced stability within microelectronic fabrications.
2. Description of the Related Art
Microelectronic fabrications are formed from microelectronic substrates over which are formed patterned microelectronic conductor layers which are separated by microelectronic dielectric layers.
As microelectronic fabrication integration levels have increased and patterned microelectronic conductor layer dimensions have decreased, it has become common in the art of microelectronic fabrication to employ when fabricating microelectronic fabrications patterned copper containing microelectronic conductor layers. Patterned copper containing microelectronic conductor layers are desirable in the art of microelectronic fabrication when fabricating patterned microelectronic conductor layers within microelectronic fabrications insofar as patterned copper containing microelectronic conductor layers typically provide microelectronic fabrications with enhanced microelectronic fabrication speed while simultaneously avoiding within microelectronic fabrications detrimental effects, such. as but not limited to detrimental electromigration effects.
While microelectronic fabrications fabricated employing patterned copper containing microelectronic conductor layers are thus desirable in the art of microelectronic fabrication, microelectronic fabrications fabricated employing patterned copper containing microelectronic conductor layers are nonetheless not entirely without problems in the art of microelectronic fabrication. In that regard, microelectronic fabrications having fabricated therein microelectronic structures, such as but not limited to microelectronic capacitor structures, fabricated employing patterned copper containing microelectronic conductor layers within microelectronic fabrications, while not being susceptible to detrimental effects such as electromigration effects, are often nonetheless susceptible to other detrimental effects, such as but not limited to interdiffusion effects and oxidation effects, which affect the stability (such as but not limited to electrical stability) of the microelectronic structures.
It is thus towards the goal of forming within microelectronic fabrications copper containing microelectronic structures with enhanced stability that the present invention is directed.
Various microelectronic structures having desirable properties, including microelectronic capacitor structures having desirable properties, have been disclosed in the art of microelectronic fabrication.
For example, Howard et al., in U.S. Pat. No. 4,471,405, discloses a thin film microelectronic capacitor structure for use within a microelectronic fabrication, and a method for fabricating the thin film microelectronic capacitor structure for use within the microelectronic fabrication, wherein the thin film microelectronic capacitor structure is formed with a capacitor electrode plate formed with enhanced stability for use within the microelectronic fabrication. To effect the foregoing result, the thin film microelectronic capacitor structure employs as a bottom capacitor electrode plate within the thin film microelectronic capacitor structure a laminate of a platinum layer formed upon a metal which forms upon thermal annealing with the platinum layer a stable intermetallic material layer.
In addition, Smith, in U.S. Pat. No. 4,890,192, discloses a thin film microelectronic capacitor structure for use within a microelectronic fabrication, and a method for fabricating the thin film microelectronic capacitor structure for use within the microelectronic fabrication, wherein the thin film microelectronic capacitor structure is formed with enhanced areal capacitance within the microelectronic fabrication. The thin film microelectronic capacitor structure realizes the foregoing object by employing when fabricating the thin film microelectronic capacitor structure a stack of three capacitor electrode plates separated by a pair of two capacitive dielectric layers interposed therebetween, where a middle capacitor electrode plate within the stack of three capacitor electrode plates is a patterned layer having a series of patterns separated by an additional series of dielectric spacer layers.
Further, Stevens, in U.S. Pat. No. 5,741,721, discloses a thin film microelectronic capacitor structure for use within a microelectronic fabrication, and a method for fabricating the thin film microelectronic capacitor structure for use within the microelectronic fabrication, wherein the thin film microelectronic capacitor structure is readily fabricated with enhanced performance properties while not incorporating heavy metals when fabricating the thin film microelectronic capacitor structure for use within the microelectronic fabrication. To realize the foregoing object, the thin film microelectronic capacitor structure employs when forming a bottom electrode plate within the thin film microelectronic capacitor structure a transition metal nitride material layer which may be thermally oxidized to form a capacitor dielectric layer within the thin film microelectronic capacitor structure.
Finally, Weng et al., in U.S. Pat. No. 5,946,567, discloses a thin film microelectronic capacitor structure for use within a microelectronic fabrication, and a method for fabricating the thin film microelectronic capacitor structure for use within the microelectronic fabrication, wherein the thin film microelectronic capacitor structure is formed with a uniform areal distribution of capacitance over a microelectronic substrate within which is fabricated the thin film microelectronic capacitor structure. To realize the foregoing object, the thin film microelectronic capacitor structure employs when forming an upper capacitor electrode plate within the thin film microelectronic capacitor structure a comparatively thin upper capacitor electrode plate contacting a capacitor dielectric layer within the thin film microelectronic capacitor structure, where the comparatively thin upper capacitor electrode plate in turn has formed thereupon a series of relatively uniformly spaced conductor stud layers which bridge to a comparatively thicker upper capacitor electrode plate further spaced from the capacitor dielectric layer within the thin film microelectronic capacitor structure.
Desirable in the art of microelectronic fabrication are additional methods and materials which may be employed for forming within microelectronic fabrications copper containing microelectronic structures, such as but not limited to copper containing microelectronic capacitor structures, with enhanced stability, such as but not limited to enhanced thermal diffusion stability and enhanced oxidation stability, which in turn provide enhanced electrical stability of the copper containing microelectronic structures.
It is towards the foregoing object that the present invention is directed.
A first object of the present invention is to provide for use within a microelectronic fabrication a copper containing microelectronic structure, and a method for fabricating the copper containing microelectronic structure.
A second object of the present invention is to provide the copper containing microelectronic structure and the method for fabricating the copper containing microelectronic structure in accord with the first object of the present invention, where the copper containing microelectronic structure is fabricated with enhanced stability.
A third object of the present invention is to provide a copper containing microelectronic structure and a method for fabricating the copper containing microelectronic structure in accord with the first object of the present invention and the second object of the present invention, which method is readily commercially implemented.
In accord with the objects of the present invention, there is provided by the present invention a copper containing microelectronic capacitor structure and a method for fabricating the copper containing microelectronic capacitor structure. To practice the method of the present invention, there is first provided a substrate. There is then formed over the substrate a first capacitor plate layer formed of a first copper containing conductor material. There is then formed upon the first capacitor plate layer a first barrier layer. There is then formed upon the first barrier layer a capacitor dielectric layer. There is then formed upon the capacitor dielectric layer a second barrier layer. Finally, there is then formed upon the second barrier layer a second capacitor plate layer formed of a second copper containing conductor material.
The method for fabricating the microelectronic capacitor structure in accord with the present invention contemplates the microelectronic capacitor structure fabricated in accord with the method for fabricating the microelectronic capacitor structure.
In accord with a second embodiment of the invention, there is also provided by the present invention a related microelectronic capacitor structure and a method for fabricating the related microelectronic capacitor structure. Within the related microelectronic capacitor structure, and in accord with the microelectronic capacitor structure of the first embodiment of the invention, there is employed a pair of barrier layers at least in part as a pair of capacitor plates within the microelectronic capacitor structure, and there is also employed for forming a capacitor dielectric layer within the microelectronic capacitor structure a dielectric material which does not derive from a material from which is formed the pair of capacitor plates.
The present invention provides a copper containing microelectronic structure and a method for fabricating the copper containing microelectronic structure, where the copper containing microelectronic structure is fabricated with enhanced stability. A first embodiment of the present invention realizes the foregoing object by employing when forming a microelectronic capacitor structure which employs a pair of capacitor electrode plates formed of a pair of copper containing conductor materials a pair of barrier layers which separates the pair of capacitor electrode plates from a capacitor dielectric layer which is also formed interposed between the pair of capacitor electrode plates.
A second embodiment of the present invention realizes the foregoing object by employing within a microelectronic capacitor structure which comprises a pair of barrier layers which serves in-part as a pair of capacitor electrode plates a capacitive dielectric layer formed from a material which does not derive from the material from which is formed the pair of barrier layers.
The method of the present invention is readily commercially implemented. The present invention employs methods and materials as are generally known in the art of microelectronic fabrication, but employed within the context of a specific ordering to provide a microelectronic capacitor structure in accord with the present invention. Since it is a specific ordering of methods and materials which provides at least in part the present invention, rather than the existence of methods and materials which provides the present invention, the method of the present invention is readily commercially implemented.